Abstract: In a video signal recording and/or reproducing apparatus including four magnetic heads mounted on a rotary drum for forming four parallel recording tracks in a repeating sequence on a recording medium with each track having an azimuth gap angle different from the azimuth gap angles of the next adjacent tracks; pilot signals having different frequencies are recorded in a superimposed manner upon the information signals recorded by the four magnetic heads, respectively, and, upon reproducing, tracking control is effected so as to ensure that the magnetic heads which recorded the pilot signals with different respective frequencies are used to reproduce the signals recorded in the respective recording tracks so that a period of a timing signal, for example, a horizontal synchronizing signal, contained in the reproduced signal will not be disturbed upon switching from one to another of the magnetic heads in the reproducing mode.

Abstract: A communication system for video information apparatus for carrying out a communication between a video information apparatus and a peripheral apparatus arranged so that a communication is repeatedly carried out at a period synchronized with a signal of a vertical period having a constant phase relation relative to a vertical synchronizing signal.

Abstract: A motor rotation control apparatus employs a comb filter circuit operable to filter out a signal component and its higher harmonics. An error signal indicative of an error between actual and target conditions of rotation of the motor is applied to the comb filter circuit after its DC component is removed. The filtered signal and the error signal are added in a circuit which produces a control signal used to control the motor rotation. In another aspect of the invention, the error signal is divided into a first digital signal having upper bits of data having a predetermined bit number and a second digital signal having the remaining lower bits of data. The lower bits of data are delayed a predetermined time and added to the error signal to compensate for lower bits of data which may be ignored in a digital-to-analog converter operable, with a limited bit number, to provide a control analog signal used to control the motor rotation.

Abstract: A data communication apparatus of a start-stop synchronizing system in which a bidirectional data communication between a master apparatus (10) and a slave apparatus (20) can be carried out through a single communication line (30). The transmission period of the master apparatus (10) and the transmission period of the slave apparatus (20) are formed as one block and this one block is repeated. Start signals X.sub.1 and X.sub.2 for use in transmitting and receiving data are transmitted only from the master apparatus (10). Since it is sufficient to provide a single communication line between the two apparatus, the construction of the system can be simplified.

Abstract: A signal translating circuit comprises first and second transistors connected to each other in such a manner that a collector of the first transistor is coupled with a base of the second transistor and an emitter of the second transistor is coupled with a base of the first transistor so as to form a negative feedback circuit arrangement, an input resistor connected between the base of the first transistor and a source of an input voltage signal for converting the input voltage signal into an input current signal to be supplied to the base of the first transistor, a biasing current source connected to the base of the first transistor, first and second current sources supplying the same currents and connected to the emitter of the first transistor and a collector of the second transistor, respectively, and means for deriving an output current signal from the collector of the second transistor.

Abstract: Information is digitized, and the digital information signals are used to produce frequency modulated signals the instantaneous frequency of which is a function of the content of the digital information signals. The frequency-modulated signals are recorded in alternate tracks with alternate recording heads having air gaps of different azimuth angles. In one embodiment, the recording heads are the rotary heads of a VTR, and the digital information signals are digital audio signals which are recorded in the same tracks as the usual video signals.

Abstract: Apparatus for recording and reproducing an information signal comprised of a video signal and an audio signal in a plurality of tracks extending obliquely on a magnetic tape includes a sample and hold circuit, an analog-to-digital converter and an encoder for converting the audio signal to a pulse code modulation (PCM) audio signal; a time base compression circuit for compressing the PCM audio signal; and two rotary magnetic heads for recording the compressed PCM audio signal in the plurality of tracks, each of the tracks being divided into a first leading audio track section, a contral video track section and a trailing audio track section, with the two heads recording one field interval of the video signal in the central track section of each track and recording the audio signal corresponding to one field interval of the video signal recorded in an adjacent track, in the first and second audio track sections of each track such that odd samples of the audio signal are recorded in each first leading audio tra

Abstract: In apparatus for reproducing a video signal which is recorded on a recording medium with a luminance component thereof non-linearly pre-emphasized and the signal portions thereof greater than a predetermined level being clipped; there are provided a non-linear de-emphasizing circuit which non-linearly attenuates the reproduced luminance component in a manner substantially complementary to the amount of the non-linear pre-emphasis, a gain control element, for example, in the form of a transistor, having a variable gain, and a compensating circuit for substantially recovering the clipped signal portions upon reproduction of the video signal, and in which the compensating circuit increases the gain of the gain control element for the portions of the reproduced luminance component at the predetermined level.

Abstract: A phase compressor for a phase modulated signal comprises n phase suppressors (n is an integer greater than 2), each of which includes an adder and a limiter. The n phase suppressors are connected in series with one another. In this case, outputs from the limiters of nth, (n - 1)th, (n - 2)th, . . . . 2nd phase suppressors are individually supplied to the adders along with outputs from the (n - 1)th, (n - 2)th, . . . . 1st phase suppressors, respectively. A reference signal is supplied to the adder of the nth phase suppressor, by which a modulated phase angle of the phase modulated signal with a wide modulation index is phase-compressed by 1/.sub.n.sub.+1. The phase compressed signal is phase-demodulated by a phase demodulator without decreasing a signal-noise ratio.

Abstract: A brushless DC motor having a plurality of stator windings and a rotor made of a magnet is driven by energizing the stator windings successively, and in which signals induced in the plurality of stator windings resulting from the rotation of the rotor are detected as position signals of the rotor and at least one of the stator windings which corresponds to the position signal is supplied with a driving signal.

Abstract: A reference carrier signal is combined with a phase modulated signal of the same basic frequency to generate an output signal the amplitude of which varies in accordance with the phase difference between the phase modulated signal and the reference carrier. The permissible modulation angle is increased by vectorally adding the phase modulated signal with a reference signal having a phase different from the comparison reference carrier. The vector sum signal is amplitude-limited so that the signal produced by the comparison will only be responsive to phase angle and not amplitude.

Abstract: A communication system for video information apparatus for carrying out a communication between a video information apparatus and a peripheral apparatus arranged so that a communication is repeatedly carried out at a period synchronized with a signal of a vertical period having a constant phase relation relative to a vertical synchronizing signal.